Emery paeker



(Model.)

- E. PARKER.

LOCK.

No. 249,789. Patented Nov. 22,1881.

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PETERS. Phullhogrlpher, Washington. l!V C.

Uniti; drames EMERY PARKER, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE N ASHUA LOCK COMPANY, OF NASHA, NE HAMPSHIRE..

LOCK.

SPECIFICATION forming part of Letters Patent No. 249,789, dated November 22, 1881.

Application filed June ll, 1881. (Model.)

Like letters in the figures indicate the sameparts.

My improvement relates to door-locks, and particularly to such as Iare intended to be used in hotels and similar buildings where it is desirable to have locks which cannot'be opened from the outside when locked upon the inside of the room.

The object of my invention is to provide a lock which can he locked and unlocked in thev usual manner from the outside when itis not locked upon the inside, and which in the latter case cannot be unlocked from the outside, and one which can be locked or unlocked from the inside at all times, whether it is locked or not from the outside.

In the accompanying drawings, illustrating my invention, Figure l is a side view of alock having my improvements, with part tf the front plate removed, so as to show the interior parts in the unlocked position. Fig. 2 is a somewhat enlarged view of the lower part of the lock, showing` the several parts ,in the position when locked from the inside and the bit of the key in the lock. Fig. 3 is a vertical section on the line a l) of Fig. 2.

A is the case of the lock, which is made in the ordinary manner.

B is the key-hole upon the outside ofthe door, and C shows the position of the key-hole upon the inside of the door, they not being opposite to each other. rlhe position of the inside key-hole is shown by dotted lines in Fig. 2.

D is the holt, E the tumblers, and F the springs, all operated in the usual manner, and constructed with two sets ol' notches for the key when used in either of the two key-holes.

The lock may be made in almost any of the ordinary forms, and, so far as my present invention is concerned, the bolt might be without tumblers.

G is a sliding block lying between and guided by the plates of the lock-case, and also by the stud or projection H, which limits the movement to the rear to the position shown in the drawings.

J is a spring'which presses the block G to the rear, and which can be compressed by the block G in moving forward or to the left, as shown in the drawings. The upper right-hand corner of the block G is slightly beveled to receive the bit ofthe key, (shown wit-hout the key in Fig. 1, and with the bit of the key resting upon it in Fig. 2.)

K is the hit of the key inthe position when inserted upon the inside oftthedoor and the bolt locked.

The operation of my invention is as follows: In the position of the parts shown in Fig. l the key can he inserted from the outside through the key-hole B, and the bolt locked or unlocked in the usual manner. When the key is inserted from the inside to lock the bolt it can be turned round to the position shown in Fig. 2. This throws the holt and leaves the bit of the key resting upon the block G, in which position it acts as a pawl against the bolt to hold -it from being forced back if another key should be used from the outside to unlock the door. As the bitot1 the key cannot pass this position it cannot be removed from the lock, and consequently must remain a sure preventative against the lock being opened from the outside until it is unlocked from the inside.

It' by accidentthe door should be locked from the outside while a person having a key was upon the inside, as might sometimes occur, the

another key remains in the outside or not@ In this case the hit of the key in turning the reverse way from the locking presses against yf bolt can be unlocked from the inside, whether.

the -side ofthe block G and forces it forward against the spring J, and passes upward to the bolt, which it throws in the usual manner. The key can then be passedaround, soas t0 be taken out of the keyhole, it' desired. By means of my invention an ordinary lock can IOO be made secure and unpiekable when looked to pass in one direction to withdraw the bolt, from the inside without interfering with any of but stops said key when the bolt is locked,

the ordinary advantages of a simple lock. substantially as described.

What I claim as my invention is- EMERY PARKER. In a door-lock, the combination of the slid- Vitnesses:

ing block G and spring J, constituting a stop THEO. G. ELLIS,

mechanism which permits the bit of the key (JHAs. L. BURDETT. 

